Seats for automobiles and trains, various sofas, office chairs, and the like, are provided with cushion bodies in the insides of their epidermis materials. For the cushion bodies, a molded body formed of material called rock wool and such, which is made by twisting stiff fibers, such as palm and hemp or thick synthetic fibers and hardening the same with a rubber and the like, and a molded body (foam body) which is formed of various foam resin materials are used.
These cushion bodies often have curved surfaces which are consisted of depression and projection form that is ergonomically satisfying so as to keep a sitting position which prevents fatigue from sitting for a long time. It is difficult to use the rock wool which requires many production processes for efficient mass production of the cushion body which has such a complicated surface form, by also considering its cushioning characteristic.
On the other hand, a foam resin cushion body is used broadly because the foam resin cushion body can be produced in a single process and various shapes can easily be obtained. Namely, the foam resin cushion body is molded in a desired form at the same time as foaming by pouring foam resin material such as, for example, foam urethane resin, into a mold.
Additionally, on the surface of the cushion body which has been molded in this manner, generally, epidermis material, such as various fiber fabric and natural or synthetic leather, is deposited. For depositing the epidermis material on the surface of the cushion body, either means for integrating the cushion body into the back surface of the epidermis material at the same time as molding of the cushion body by adsorbing the epidermis material along a cavity surface of the mold and by pouring the foam resin material into the mold, or means for molding the cushion body in a desired form and then covering the surface of the obtained cushion body with the epidermis material and fixing the same to the surface, is employed.
In the case of using the afore-mentioned means for integrating at the same time as molding, when setting the epidermis material along the inner surface of the mold, the epidermis material is adsorbed along the inner surface of the mold using suction means. However, in order to deform the epidermis material along the surface of the cushion body having a complicated surface form as mentioned above, the epidermis material itself needs to be good in elasticity. Nevertheless, for some materials, the elasticity has a limit. Therefore, when the surface form of the cushion body becomes complicated, numerous wrinkles tend to appear particularly between a seating surface and a peripheral side surface, and a lot of efforts are made to correct this.
Additionally, by the means, the cushion body and the epidermis material are integrated at the whole surface. Therefore, for example, if a strong force is applied in the direction that the epidermis material moves on the surface of the cushion body when being used, a shearing force works between the epidermis material and the cushion body, thereby possibly causing an abrasion of the epidermis material by tearing a part of the cushion body. Moreover, in order to prevent the afore-mentioned wrinkles from appearing, materials which may be used as the epidermis material are naturally limited, and it is preferred that a slight movement may be tolerated between the epidermis material and the cushion body so that an excessive force does not apply between the two. Therefore, a means for putting the epidermis material over the obtained cushion body after molding the cushion body in the desired form has become more frequently employed, rather than using a means for integrating the epidermis at the same time as the molding of the cushion body.
When putting the epidermis material over such cushion body which is made from the foam resin material, a method of using the molded hook and loop fastener which is made from a thermoplastic resin is generally employed. For example, firstly, the molded hook and loop fastener, which comprises multiple engaging elements (male engaging elements), is set on the cavity surface of the mold which molds the cushion body. At this point, the molded hook and loop fastener is mounted and fixed on a protruding surface portion of the mold bottom surface which corresponds to a recess surface of the cushion body with an engaging elements formation surface of the molded hook and loop fastener oriented toward the protruding surface portion.
Secondly, by pouring the foam resin material into the mold on which the molded hook and loop fastener is mounted so as to foam-mold the cushion body, at the same time as the molding of the cushion body, the molded hook and loop fastener is integrated into the recess surface of the cushion body with the engaging elements exposed outside. Note that, at the time of the foam-molding, it is important to prevent the foam resin material of the cushion body from flowing into a region where the engaging elements of the molded hook and loop fastener are formed.
Then, the epidermis material is put over the surface of the cushion body which has been obtained by the afore-mentioned foam-molding. The epidermis material is made from various materials such as pile woven and knitted fabrics, natural and synthetic leather, and synthetic leather and is previously formed into a bag in accordance with the external form of the cushion body. At this time, by pressing female engaging elements which are disposed on the back surface of the epidermis material against the engaging element forming region of the molded hook and loop fastener which is integrated into the cushion body so as to fasten the epidermis material to the molded hook and loop fastener along the recess surface of the cushion body, and therefore the epidermis material is prevented from coming off the cushion body.
As mentioned above, a molded hook and loop fastener that can prevent a foam resin material from intruding into an engaging element forming region when performing a foam-molding so as to integrate the molded hook and loop fastener into a cushion body is disclosed in JP 2010-162339 A (Patent Document 1), for example.
For example, as illustrated in FIG. 11, a molded hook and loop fastener 70 which is described in Patent Document 1 comprises multiple hook and loop fastener parts 71, each of which has an engaging element forming region 75 which is surrounded by a longitudinal protective wall 73 and a lateral protective wall 74 on the front and rear end edge sides, and a connection part 72 which establishes connection between the edges in the longitudinal direction of the adjacent hook and loop fastener parts 71 with a predetermined interval.
Each hook and loop fastener part 71 comprises a flat plate-shaped backing 76, multiple hook-shaped engaging elements (male engaging elements) 77 which are disposed to stand on the entire surface of the backing 76, left and right longitudinal protective walls 73 which are disposed to stand on left and right side edge portions of the backing 76 along the longitudinal direction so as to interpose the engaging elements 77 between them, a lateral protective wall 74 which is disposed to stand between the left and right longitudinal protective walls 73 along the width direction, a protruding portion 78 which fixes a monofilament composing the connection part 72, and a linear magnetic body 79 which is disposed along the longitudinal direction.
In addition, the front and rear end edges of each hook and loop fastener part 71 comprises a parallel portion 71a which is disposed parallel to each other between the hook and loop fastener parts 71 which are adjacent in the longitudinal direction, and inclined portions 71b which are disposed on both left and right sides of the parallel portion 71a. In this case, the parallel portion 71a has the same dimension in the width direction as the connection part (monofilament) 72.
Multiple engaging elements 77 which are disposed on each hook and loop fastener part 71 is aligned with predetermined intervals from each other along the longitudinal direction and the width direction of the backing 76.
The longitudinal protective wall 73 each has three rows of walls each on the left and right sides thereof, and the wall of each row are configured by multiple longitudinal walls 73a which are disposed at a predetermined pitch. In this case, between the walls of the adjacent rows, the longitudinal walls 73a are disposed in a staggered manner so as to be alternating with each other. Besides, the lateral protective wall 74 is configured by the engaging elements 77 which are aligned in the width direction and multiple lateral walls 74a which are disposed along the with direction.
The protruding portion 78 which fixes the monofilament is formed at a substantially central portion of the hook and loop fastener part 71 in the width direction, protruding from the backing 76 in a block shape, and buries the monofilament all through the region of the hook and loop fastener part 71. The linear magnetic body 79 which is disposed on the hook and loop fastener part 71 is fixed by a portion of the same being buried in a fixing part 80 which protrudes in the block shape from the backing 76.
As described above, the connection part 72 which establishes connection between the hook and loop fastener parts 71 is formed of a synthetic resin linear monofilament which is buried in the protruding portion 78 of each hook and loop fastener part 71. While the monofilament is buried in the protruding portion 78 in the region of the hook and loop fastener part 71, the monofilament is exposed outside between the adjacent hook and loop fastener parts 71, and the connection part 72 is formed of the exposed portion of the monofilament. To dispose such connection part 72 enables the molded hook and loop fastener 70 to be bent easily in the width direction.
When producing the molded hook and loop fastener of Patent Document 1 having the configuration as mentioned above, firstly, a continuous long hook and loop fastener member (hereafter referred to as a “primary hook and loop fastener member”) which has not yet been cut into multiple hook and loop fastener parts 71 is produced. The primary hook and loop fastener member is produced by means of a production device including a die wheel which is driven rotationally, an extruding nozzle which supplies molten resin to the circumferential surface of the die wheel, and a supply portion which supplies the monofilament and the linear magnetic body 79 from an upstream position of a position where the molten resin for the die wheel is supplied. In this case, on the circumferential surface of the die wheel, cavities for molding the engaging elements 77 and cavities for molding the longitudinal wall 73a and the lateral wall 74a and such are formed.
After producing the long primary hook and loop fastener member by means of such a production device, a portion of the obtained primary hook and loop fastener member is cut off at any point all through the width direction so as to preserve the monofilament which forms the connection part 72. In this way, the molded hook and loop fastener 70 of Patent Document 1 as illustrated in FIG. 11 is produced.
The molded hook and loop fastener 70 of Patent Document 1 obtained in this way is adsorbed and fixed on the cavity surface of the mold so as to make the engaging elements 77 opposed to the cavity surface by using magnetic force of a magnet which is previously installed at the mold for molding, when performing a foam molding of the cushion body.
At this time, in the molded hook and loop fastener 70, the connection part 72 (monofilament) which establishes connection between the hook and loop fastener parts 71 can be easily bent. Therefore, for example, even if a portion of the mold for fixing the molded hook and loop fastener 70 (protruding surface portion) is curved, it becomes possible to adsorb and fix the molded hook and loop fastener 70 stably to the cavity surface of the mold with the molded hook and loop fastener 70 curved in the width direction.
Additionally, as for the molded hook and loop fastener 70, the engaging element forming region 75, on which multiple engaging elements 77 are disposed, is surrounded by the longitudinal protective wall 73 and the lateral protective wall 74. Therefore, when performing a foam molding of the cushion body, the foam resin material can be prevented from intruding into the engaging element forming region 75 over the longitudinal protective wall 73 and the lateral protective wall 74. Accordingly, even after the cushion body is foam-molded, a fastening force by the engaging elements 77 can be obtained in the engaging element forming region 75 of the molded hook and loop fastener 70. Therefore, when putting the epidermis material over the cushion body, the back surface of the epidermis material can be stably fastened on the molded hook and loop fastener 70.